In 2007, the global market for wireless products for factory automation was only 500,000 products, according to the market analyst, IMS Research. This included wireless sensors, operator terminals, PLCs, remote I/O and wireless access points. By 2013, the company forecasts, sales will increase to almost four million products – a substantial increase, but still small compared to the uptake of wireless technologies in offices.

The biggest obstacle to a wider adoption of wireless communications, according to IMS, is reliability. The presence in factories of machinery that can disrupt wireless signals, together with the increasing importance of gathering detailed, reliable machine data, has convinced most end-users and OEMs that, for now at least, wired systems are best.
 
However, IMS adds that a growing number of users are experimenting with wireless products specifically designed and ruggedised for use in factories.
 
The falling cost of wireless-enabled products is providing an incentive for these users to convert from wired networks, or to use both types of network alongside each other. This is particularly attractive in the current economic climate, says IMS, because the initial outlay to install a wireless network is generally lower than that for a wired network. For example, significant cost savings are possible in applications such as a wastewater treatment plants where pumps can be located several hundred metres from the control room.
 
The adoption of wireless networks for applications such as condition monitoring can also eliminate the cost of components such as sliprings that have been needed previously to monitor rotating components. With wireless sensors, users can monitor applications incorporating rotating parts at a much lower cost.
 
Battery-powered wireless sensors can also be used to monitor areas of plants unsuited to wired sensors.
 
IMS predicts therefore that between 2007 and 2013, global shipments of wireless systems for factory automation applications will grow by an average of 40% a year. This growth will be driven, in part, by automation component suppliers who to see wireless as the next big step in boosting plant efficiencies.